orangepotato Welcome to Spine!
There are several ways to approach your issue, but I guess the first thing I should tell you is that we are planning to add Physics constraints in the next version, Spine 4.2. This would be useful to more easily create overlapping or follow through movement for a particular bone, e.g. animating the hair bones to overlap or follow through the head bone.
As for ways to improve your workflow with current features, you can more easily apply changes to the entire animation by using the Adjust button on the Dopesheed view or using the Graph view.
If you turn on the Adjust button, you can edit multiple keys at once. The following tip will help you understand how to use this feature: https://esotericsoftware.com/spine-tips#20-float
By the way, you can select all keyes currently displayed in the Dopesheet view can be selected by pressing
Ctrl+A (for macOS,
cmd+A) when the Dopesheet view is active. The currently active view is indicated by an underline in the view name:
You can also box-select multiple keys in the Graph view and change the values of those keys at once. To change the values of those keys, you can either drag them up or down or use the Favor tool.
When changing key values by dragging, enabling Snapping makes it easier to align values to a specific key.
For details on how to use the Favor tool, please watch the video in the user guide. Personally, when I want to calm down a movement that has been moved too far, I select all the target keys, turn the favor slider mode to the
Setup mode, and move the favor slider to bring those keys closer to the setup pose.
Other than that, a good use of constrains will reduce the number of keys that you have to manually modify by yourself. For example, as shown in the tip below, you can animate a bone for the maximum movement, then adjust a transform constraint's mix to control how much that aspect of the animation is applied: http://esotericsoftware.com/spine-tips#38-hat-transform
Although only one bone is constrained in the tip above, multiple constrains can be created for a single target bone, or more bones can be managed using Path constraints.
For more information on how to use the Path constraints for that purpose, our new Spine tip posted on X just recently may be helpful:
(I should mention that this wonderful idea was conceived by Erika.)
Note that there are so many uses for constraints that what I have mentioned is only a small part of them. If you tell us what kind of movement you are having particular trouble managing, we may be able to come up with more specific advice on how to improve your rig so that animations can be easily fixed, even if you have to add changes later.